Normal healthy aging has been found to have statistically significant effects on the oropharyngeal swallow. In patients with Alzheimer's disease, since most are 60+ years old, we can see these normal aging effects on swallow physiology but also significant changes in sensory perception including poor recognition of food on a plate or liquid in a cup, poor recognition of food in the mouth and apraxia of swallow, meaning they cannot coordinate tongue movements to initiate a swallow in the mouth or to propel the food back to the pharynx. Since they don't recognize food as food in their mouth, Alzheimer's patients do not respond to commands to swallow and can take a very long time to be fed by a caregiver, often resulting in inadequate nutrition and hydration. This project proposes to identify the ability of selected taste (sour) and carbonation to heighten the Alzheimer's patients' ability to recognize liquid in the mouth, produce a timelier and motorically normal swallow, and increase their hydration and nutrition. This proposal will meet the goals of the T1 Translational Research: Novel Interventions for Prevention and Treatment of Age-Related Conditions by examining the impact of two types of sensory-enhanced bolus swallows in dysphagic patients with Alzheimer's disease: 1. For each patient with Alzheimer's disease, select either the carbonated or the sour bolus type as best for the patient, and determine whether selected measures of oropharyngeal swallow function from videofluoroscopy (VFG) and the modified barium swallow (MBS), will improve significantly while swallowing selected 3 and 10 ml thin liquid as compared to the same measures in each patient's baseline 3 and 10 ml liquid swallows of non-sensory enhanced boluses. 2. Measure whether sensory changes are maintained after 1 swallow of a sensory bolus followed by 4 swallows of the same 3 and 10 ml volumes of thin liquid without the sensory enhancement, whether volume effects the extent of change in swallow measures and if the same effects are maintained at 2 days, 2 weeks, and 1 month after the baseline study and therefore continue to improve the oropharyngeal swallow. 3. Determine whether length of time since diagnosis of Alzheimer's disease or patient age correlate with the effectiveness of each of the two sensory-enhanced liquids. 4. Determine agreement between results of the clinical judgments made during the MBS and the lab assessment of these measures and observations from the MBS. 5. Determine if caretaker judgment about ease of feeding on the caregiver questionnaire correlates with changes in swallow measures and observations, and to examine caregiver compliance with introduction of the selected liquid type.